Our group focus the research on development of new synthetic methodologies in organic chemistry, including hypervalent iodoniums and asymmetric catalysis. Meanwhile, we also focus on the exploration of controlled release of fragrances.
Organocatalysis with Iminophosphoranes:
Organocatalysis is the chemical process catalyzed by small organic molecular compounds, which gradually becomes one of the most popular field in organic chemistry these year. It can be employed in diverse synthetic cascade sequences to quickly construct complex bonds, stereocenters and polycyclic frameworks. Compared with metal catalyzed asymmetric synthesis, organocatalysis has obvious advantages: simple operation, usually no need of water and oxygen free treatment, avoiding the pollution of heavy metal. Most importantly, organocatalysis generally gives rise to outstanding stereoselectivity, which can be applied to asymmetric aynthesis.
Our group has carried out a lot of research and developed new chiral catalysts with high efficiency and easy access. We have developed a series of chiral iminophosphorane catalysts by using cheap natural tartatic acid as raw material. As Brønsted base, they can catalyze the asymmetric chlorination of substituted indoles and replace the excellent enantioselectivity (up to > 99% ee).
(see http://pubs.acs.org/doi/abs/10.1021/acs.orglett.5b02323)
Iodonium Enabled Arylations:
Diaryliodonium salts (Ar2IX), owing to their favorable safety profile, ease of handling, air and moisture stability, are particularly attractive arylating reagents in organic synthesis. Due to the high electron-deficient nature of its positive iodide ion and its easy-to-leave characteristics, its C(sp2)-I bond is easier to be activated than the general halogenated aromatic carbon-halogen bond. In recent years, a growing interest has been focused on the exploration of their unique reactivities that facilitate novel reaction pathways.
Since the beginning of 2011, our team has carried out research on the arylation reactions using diaryliodonium salts and completed the expansion of the aromatic conjugation of multiple aromatic ring precursors. These include the arylation of triarylamine and naphthalimide, synthesis of the 4,5-benzocoumarins and triphenylene.
In 2018, the topic of “Internal aryl migration of dialyliodonium salts: access to ortho iodo dialyl ethers” in Angewandte Chemie reported our group`s research work in the field of dialyliodonium salts. (see https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201806405)
Profragrance for controllable release:
Perfume is an important part of fine chemicals, its application can bee seen everywhere in our daily life. Due to the rapid volatility and oxidizable properties of perfumes, the value of its application will be greatly reduced， it`s a challenge to find out how to store the perfume molecules and prolong the time of fragrance release by technical means.
Profragrance is the substance synthesized by the reversible reaction of perfume and other substances, which is more stable and not volatile. The covalent bond that links the fragrance to its substance can respond to the external stimulation, such as enzymes (as from micro-organisms), hydrolysis (such as the result of a change of pH), light stimuli (in particular ambient daylight), oxidation (with oxygen from the air) and temperature changes.
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